Lactobacillus paracasei is a species of lactic acid bacteria often used in the fermentation of dairy products. It’s found in the human intestinal tract and mouth, but also in foods such as yogurt and naturally fermented vegetables and milk.
L. paracasei is similar to other strains of Lactobacillus bacteria, including L. casei and L. rhamnosus. However, each strain is differentiated from one another by the way in which it ferments and the different criteria required for growth. L. paracasei has been found to show specific differences compared to other Lactobacillus species, particularly in its ability to withstand higher temperatures.
Lactobacillus paracasei grows well in ripening cheese and is very effective at breaking down proteins into amino acids.
L. paracasei has been found to boost the immune system. Studies show that children supplemented with cow’s milk or rice containing L. paracasei are less likely to pick up common infectious diseases when attending daycare.
Studies in mice have also shown that L. paracasei enhances immune system function by increasing the production of cytokines. It also boosts the activity of natural killer cells, lymphocyte proliferation and antibody production. This powerful probiotic has even been found to ameliorate the symptoms of influenza virus infection in mice, and increase the survival rate of mice infected with E.coli.
Alongside its immune-boosting properties, L. paracasei can help to inhibit harmful pathogens such as Shigella dysenteriae, Staphylococcus aureus, Cronobacter sakazakii, Escherichia coli, and Candida albicans. Supplementation of fermented milk containing L. paracasei was found to lead to improved gut microbiota, with higher populations of healthy Lactobacilli bacteria. Yeast infections such as Candida were also inhibited. Lactobacillus paracasei also helps with dental health, inhibiting the growth and spread of bacteria associated with periodontal disease.
The anti-inflammatory properties of L. paracasei are also very important. As well as fighting off infection, L. paracasei modulates inflammatory processes in the body by increasing the release of pro-inflammatory chemicals called cytokines. It also helps to stimulates the innate immune system.
In the case of Salmonella, Lactobacillus paracasei has been found to reduce the number of potentially harmful pro-inflammatory cytokines and chemokines.
Those with allergies are also advised to add Lactobacillus paracasei to their probiotic intake. This particular strain can help to reduce nasal symptoms and airway inflammation caused by hay fever and other seasonal allergies. It’s especially effective in allergic rhinitis, with several studies showing that it helps to improve symptoms of nasal congestion, swollen eyes and itching.
When it comes to digestion, Lactobacillus paracasei is often included in probiotic formulas for improving gut health. It helps to boost the number of beneficial Bifidobacteria and Lactobacilli in the gut, while also reducing harmful bacteria.
At the same time, L. paracasei helps to strengthen the intestinal barrier and improve absorption of nutrients from food. When taken in conjunction with other probiotic strains, it can promote intestinal epithelial cell growth and protect the intestinal barrier from chemicals and pathogens.
Nocerino, R et al. "Cow's milk and rice fermented with Lactobacillus paracasei CBA L74 prevent infectious diseases in children: A randomized controlled trial." (2015)
Wassenberg, J et al. "Effect of Lactobacillus paracasei ST11 on a nasal provocation test with grass pollen in allergic rhinitis." (2011)
Chen, YP. "Effects of Lactobacillus paracasei 01 fermented milk beverage on protection of intestinal epithelial cell in vitro." (2016)